As a general rule this is correct, in fact all Chapter 3 racesways are now required to be. Listing simply isn't a requirement of the root definition.
Until it was made a general rule by the restructuring and direct introduction in the various specific Chapter 3 raceway Articles in the 2002 Edition, several classes of raceway, such as Flexible Metal Conduit (Art 348) or Flexible Metal Tubing (Art 360.6), were NOT required to be listed and many manufacturer's products weren't. Look at how many Chapter 3, Section 3xx.6 are "sidebarred" indicating it is a new requirement.
Several States have yet to adopt the 2002 Edition so, techically listing is not yet a requirement in those States.
For Class 2 or 3 wiring there's really no safety or technical reason garden hose couldn't be used as a raceway and, in fact, Art 725 wouldn't prohibit it - even in the 2005 Edition.